fix issue89 - allow py.test.mark decorators to be used with classes

(if you are using >=python2.6)
also allow to have multiple markers applied at class level
and test and fix a bug with chained skip/xfail decorators:
if any of the conditions is true a test will be skipped/xfailed
with a explanation which condition evaluated to true.

--HG--
branch : trunk

doc/test/plugin/mark.txt

@@ -39,38 +39,43 @@ and later access it with ``test_receive.webtest.args[0] == 'triangular``.
 
 .. _`scoped-marking`:
 
-Marking classes or modules 
+Marking whole classes or modules 
 ----------------------------------------------------
 
-To mark all methods of a class set a ``pytestmark`` attribute like this::
+If you are programming with Python2.6 you may use ``py.test.mark`` decorators
+with classes to apply markers to all its test methods::
+
+    @py.test.mark.webtest
+    class TestClass:
+        def test_startup(self):
+            ...
+
+This is equivalent to directly applying the decorator to the
+``test_startup`` function. 
+
+To remain compatible with Python2.5 you can instead set a 
+``pytestmark`` attribute on a TestClass like this::
 
     import py
 
     class TestClass:
         pytestmark = py.test.mark.webtest
 
-You can re-use the same markers that you would use for decorating
-a function - in fact this marker decorator will be applied
-to all test methods of the class. 
+or if you need to use multiple markers::
+
+    import py
+
+    class TestClass:
+        pytestmark = [py.test.mark.webtest, pytest.mark.slowtest]
 
 You can also set a module level marker::
 
     import py
     pytestmark = py.test.mark.webtest
 
-in which case then the marker decorator will be applied to all functions and 
+in which case then it will be applied to all functions and 
 methods defined in the module.  
 
-The order in which marker functions are called is this::
-
-    per-function (upon import of module already) 
-    per-class
-    per-module 
-
-Later called markers may overwrite previous key-value settings. 
-Positional arguments are all appended to the same 'args' list 
-of the Marker object. 
-
 Using "-k MARKNAME" to select tests
 ----------------------------------------------------
 

doc/test/plugin/skipping.txt

@@ -65,6 +65,18 @@ for skipping all methods of a test class based on platform::
             #
 
 The ``pytestmark`` decorator will be applied to each test function.
+If your code targets python2.6 or above you can also use the
+skipif decorator with classes::
+
+    @py.test.mark.skipif("sys.platform == 'win32'")
+    class TestPosixCalls:
+    
+        def test_function(self):
+            # will not be setup or run under 'win32' platform
+            #
+
+It is fine in both situations to use multiple "skipif" decorators
+on a single function. 
 
 .. _`whole class- or module level`: mark.html#scoped-marking